Brompton Fenders:
Fits all Brompton bikes. 16" tyres, fits any width.
700C fenders:
Fits 700C and 28" wheels. Good clearance up to 700x32C. More than 32C have short clearence, and need more care when fitting but looks awesome.
700C fenders also fits 26" wheels with big tyres: MTB and Baloon type tyres. Good protection and clearence is provided for 26"x1,75 to 26"x2.30.
26" fenders:
Fits slim city tyres with 26" wheels. Perfect protection and clearence for 26" up to 1,50.